It dropped in 2015 with the creative title “Chad Kelly” and includes mostly mentions of you-know-who and “swag,” and, thanks to some fine folks in Alabama, has its own video, complete with fire and puppies and kittens and Donald Trump.

Oh, and for the classy fans, ESPN’s Rece Davis was kind enough to provide a dramatic reading of the lyrics.

Incredibly, this is not what makes Kelly the most interesting Mr. Irrelevant in NFL draft history and it’s not what makes him the most intriguing addition to the Broncos this offseason.

Everything else did that. From his Hall of Fame pedigree, to past transgressions off the field, to his recent injuries, to — and perhaps most important — his NFL potential that earned him the label as head coach Vance Joseph’s “favorite quarterback in the draft.”

“He’s a tough guy. He’s smart,” Joseph said. “He’s made some childish mistakes in the past, but he’s learned from those things, so I’m comfortable with him.”

The Broncos selected Kelly, the nephew of former NFL great Jim Kelly, at No. 253 in the seventh round Saturday after a sharp fall from his once-projected second-round slot. The kid who set 25 school records in only 22 games at Mississippi joins a young quarterback room that includes fellow seventh-rounder Trevor Siemian, first-rounder Paxton Lynch, a new pass-happy playbook and yet another open competition to determine the starter.

Interviews with Kelly typically begin or end or focus entirely on two things: the incidents that cast a shadow on his college career and pre-draft process, and his uncle.

Kelly was kicked off Clemson’s football team in the spring of 2014 for “conduct detrimental to the team” after a shouting match with coaches. He transferred to junior college — East Mississippi Community College — and helped it to a national title, then promptly committed to Ole Miss in early December 2014. Less than two weeks later, he was arrested after an altercation a Buffalo, N.Y., nightclub but reached a plea deal and accepted community service. Two years later, a video surfaced of Kelly taking to the field after a fight broke out at his younger brother Casey’s high school football game. Kelly apologized, admitted he made a “bad decision” and moved on.

“To be honest with you, what bums me out is how everybody keeps bringing up Chad’s past,” said his uncle, Jim Kelly, the Hall of Fame and former Buffalo Bills quarterback. “It was three years ago, people. Get over the damn thing! He wasn’t even at Ole Miss when all this stuff happened. The one that probably bothers more than anything was when they talk about him being involved in a brawl at his younger brother’s game. He wasn’t involved in no brawl. Just because some kid put on a post ‘Chad Kelly involved in a brawl’ everybody thinks he was.

“Put it this way: If it were me, and my little brothers, Danny or Kevin, were on the bottom of a pile and about four or five guys on top were kicking him, what would you do? Stand there and watch? Heck, no.”

That Kelly intensity cost Chad in years past. And on draft weekend.

But it’s also why he’s now wearing orange and blue.

Prior to the draft, Joseph and general manager John Elway stressed a culture shift in Denver. The Broncos, coming off their first playoff-less season in six years, needed to get meaner. They needed to get tougher and bigger up front. They needed swag and an edge and whatever falls under the umbrella of “juice,” Joseph’s latest descriptor.

They believe they got all of that in offensive tackle Garett Bolles, their first-round tackle out of Utah who overcome a difficult childhood to be the 20th pick in the draft. They believe they got it in DeMarcus Walker, the pass rusher out of Florida State taken in the second round. They believe they got it in their four new linemen signed in free agency — guard Ron Leary, offensive tackle Menelik Watson, nose tackle Domata Peko and defensive end Zach Kerr.

And they believe, wholeheartedly, they got it in Chad Kelly.

“The one thing about him is he’s a great competitor. I think that’s why we’re really excited about him,” Elway said. “He makes a lot of plays and takes some chances, but he’s a great competitor and he’s got great lineage.”

Jim Kelly’s vote of confidence in his nephew, while biased, struck a chord with Elway. His latest endorsement should, too.

“There’s no doubt his competitiveness is just unmatched, along with his work ethic,” Jim Kelly said. “He’s a football junkie. From the working out to watching film, the kid loves the game of football. Nowadays, it’s your life. I know for a couple of months I didn’t even pick a football up because I knew my arm needed rest. But these guys, they’re working all the time. It’s a little different now than when it was back when John and I played.”

Butch Dill, Getty Images

Quarterback Chad Kelly #10 of the Mississippi Rebels scrambles for yardage during the first half of an NCAA college football game against the Auburn Tigers on Oct. 29, 2016 in Oxford, Miss.

Sean Gardner, Getty Images

Quarterback Chad Kelly #10 of the Mississippi Rebels looks to throw a pass during warm-ups before playing against the Oklahoma State Cowboys during the Allstate Sugar Bowl at Mercedes-Benz Superdome on Jan. 1, 2016 in New Orleans, La.

Butch Dill, Getty Images

Quarterback Chad Kelly #10 of the Mississippi Rebels throws a pass during the first half of an NCAA college football game against the Auburn Tigers on Oct. 29, 2016 in Oxford, Miss.

Stacy Revere, Getty Images

Quarterback Chad Kelly #10 of the Mississippi Rebels is seen on the bench during the game against the Oklahoma State Cowboys during the third quarter of the Allstate Sugar Bowl at Mercedes-Benz Superdome on Jan. 1, 2016 in New Orleans, La.

Sean Gardner, Getty Images

Quarterback Chad Kelly #10 of the Mississippi Rebels celebrates their 48-20 win over the Oklahoma State Cowboys during the trophy presentation after the Allstate Sugar Bowl at Mercedes-Benz Superdome on Jan. 1, 2016 in New Orleans, La.

Sean Gardner, Getty Images

Quarterback Chad Kelly #10 of the Mississippi Rebels celebrates with fans after their 48-20 win over the Oklahoma State Cowboys in the Allstate Sugar Bowl at Mercedes-Benz Superdome on Jan. 1, 2016 in New Orleans, La.

Stacy Revere, Getty Images

Quarterback Chad Kelly #10 of the Mississippi Rebels celebrates their 48-20 win over the Oklahoma State Cowboys during the trophy presentation after the Allstate Sugar Bowl at Mercedes-Benz Superdome on Jan. 1, 2016 in New Orleans, La.

Butch Dill, Getty Images

Quarterback Chad Kelly #10 of the Mississippi Rebels greets fans as they walk down Walk of Champions in the Grove before an NCAA college football game against the Auburn Tigers on Oct. 29, 2016 in Oxford, Miss.

Last weekend, when the first two days of the draft had passed and his name still hadn’t been called, Chad Kelly headed downstairs in his home in Buffalo to spend his two final nights as an NFL prospect on a cold basement floor.

He could have slept in his bed. He could have awakened well-rested for the stressful day ahead.

“I really wanted to feel what rock bottom was like,” he said. “I was just itching to get picked and to see what it would feel like having that nasty feeling inside. I’ll remember that feeling of those first two, three days (of the draft) every single day of my life. That’s just going to motivate me every single time I go out there.”

Saturday afternoon, as picks 249, 250, 251 flew off the board, Kelly headed outside with his brother Casey to blow off steam.

“We starting throwing the football and I was using my left hand,” Chad said. “I told him, ‘I guess I’m going to have to start throwing with my left to try to get me a job.’ About a minute later, the Broncos called.”

Opportunity called.

Chad, as well as Jim, said the former’s hope in all of this was to simply make his parents proud and to provide them an easier life. His mom, Charlene, is a teacher. His father, Jim’s younger brother, Kevin, works at a grocery store.

“I just want to see them happy throughout the whole process. They just wanted to see me happy but to also keep working hard and keep the faith,” Chad said. “Bad things have happened in the past, and we can only look forward. If we keep doing that, good things can come, so long as I stay humble and focused.”

But the focus now, the first year of his NFL career, will be primarily about rehabilitation. Kelly’s impressive two years at Mississippi were cut short by a torn ACL and lateral meniscus last November. Surgery on his knee was followed by surgery on his right wrist, when he tore a ligament while doing pull-ups just weeks before the draft.

Kelly’s past kept him out of the NFL combine, and his last major shot to impress college scouts was cut off, too: the final 50 or so passes of his college career, at his pro day, never happened.

His plan in 12 months could look wholly different.

***

Last Saturday evening, Elway sat before a room of reporters and cameras inside the Broncos’ Dove Valley headquarters and smiled widely as he reviewed his eight additions in the draft.

He knew one of the first questions would be about that quarterback they picked at the end, the one that forced the NFL world to awaken from its draft slumber.

The Broncos picked who? Chad Kelly?!

“I called his uncle, and he said he’s a good kid,” Elway said. “I said, ‘OK. That’s all I need.’ I trust Jim with that.”

Elway knew the collective concerns were of Kelly’s red flags, the two biggest ones a prospect could have: so-called “character” issues and serious injuries.

Elway also knew what the tape and stats showed.

In only 22 career games at Ole Miss, Kelly amassed 6,800 yards passing and 50 passing touchdowns, plus 832 yards rushing and 15 rushing touchdowns. In 2015 — leading Mississippi to wins over Alabama, Auburn and LSU before a Sugar Bowl victory over Oklahoma State — Kelly totaled 4,042 yards passing (10th in FBS), 31 passing TDs (tied for ninth) and added 663 yards rushing and 10 rushing scores. Kelly was named the 2016 Sugar Bowl MVP, becoming the first Mississippi player to win the award since Archie Manning in 1970.

The two-time second-team All-SEC selection had the arm and the guts to sling it without fear or hesitation. His arm strength has been documented and dissected. His mobility and athleticism are obvious. His decisions may need refinement, but his ceiling is high. Very high.

The Broncos’ quarterback group of two grew to three through the draft, as Joseph promised it would. And their quarterback competition of 2017 still features Siemian and Lynch. But the future?

After a June trip to California with his cousin and brother — the reward for being Mr. Irrelevant — Kelly’s future includes simply “proving them wrong.” The rapper turned NFL quarterback is here for a job. One job.

“It’s now or never,” he said. “I have a great opportunity ahead of me, and I want to prove to everybody that I’m not the same person I was a couple of years ago.”

Chad Kelly, QB

-Checkered off-the-field history includes dismissal from Clemson football team for conduct detrimental to team (April 2014), arrest for altercation at a nightclub in Buffalo (December 2014), rushing the field during brother’s high school football game (October 2016).

Nicki Jhabvala is the lead Broncos and NFL beat writer for The Denver Post. She was previously the digital news editor for sports. Before arriving at The Post in 2014, she spent nearly two years as a senior staff editor at The New York Times and five years at Sports Illustrated.

The Broncos last spring entered the middle rounds of the NFL draft on the hunt for game-breaking talent. And when Carlos Henderson (third-round pick) and Isaiah McKenzie (fifth) started making plays under the glaring August sun at training camp, it appeared Denver would have a youthful injection to its sagging offense in 2017.